On Mon, Sep 02, 2013 at 07:32:53AM +0000, Lu Jingchang-B35083 wrote:
> > > > > > > + chan->private = fn_param;
> > > > > > why do you need to use chan->private?
> > > > > [Lu Jingchang]
> > > > > The private used here is to store the slot_id information, which
> > must
> > > > be used
> > > > > by the DMAMUX in alloc_chan_resources function. Thanks.
> > > > Why dont you pass this in struct dma_slave_config memeber slave_id
> > for
> > > > this.
> > > [Lu Jingchang-b35083]
> > > I will drop this private and setup the slave_id directly in the filter
> > function.
> > why in filter? before calling prepare function you can set the slave
> > config
> How about change the filter_fn to follow:
> static bool fsl_edma_filter_fn(struct dma_chan *chan, void *fn_param)
> {
> struct fsl_edma_filter_param *fparam = fn_param;
> struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);
> unsigned char val;
>
> if (fsl_chan->edmamux->mux_id != fparam->mux_id)
> return false;
>
> val = EDMAMUX_CHCFG_ENBL | EDMAMUX_CHCFG_SOURCE(fparam->slot_id);
> fsl_edmamux_config_chan(fsl_chan, val);
> return true;
> }
> In fact the slot_id isn't need elsewhere, and if the filter return true,
> This channel should be to this request. So no need to save the slave id, Right?
something like
static bool fsl_edma_filter_fn(struct dma_chan *chan, void *fn_param)
{
struct fsl_edma_filter_param *fparam = fn_param;
struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);
if (fsl_chan->edmamux->mux_id != fparam->mux_id)
return false;
return true;
}
in thedriver which calls this:
before prep:
config->slave_id = val;
dma_set_slave_config(chan, slave);
~Vinod
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